Radio resources messaging for a mobile station in an unlicensed wireless communication system

ABSTRACT

An unlicensed wireless service is adapted to generate the interface protocols of a licensed wireless service to provide transparent transition of communication sessions between a licensed wireless service and an unlicensed wireless service. In one embodiment, a mobile station includes level  1 , level  2 , and level  3  protocols for licensed wireless service and an unlicensed wireless service. An indoor base station and indoor network controller provide protocol conversion for the unlicensed wireless service into a standard base station controller interface of the licensed wireless service.

CLAIM OF BENEFIT TO RELATED APPLICATIONS

This application is a continuation of U.S. patent application Ser. No.10/688,470 filed Oct. 17, 2003, now U.S. Pat. No. 7,127,250, entitled“Apparatus and Method for Extending the Coverage Area of a LicensedWireless Communication System Using an Unlicensed WirelessCommunication”, which claims the benefit of U.S. Provisional PatentApplication No. 60/419,785, filed Oct. 18, 2002, entitled “Method forExtending the Coverage Area of a Licensed Wireless Communication systemUsing an Unlicensed Wireless Communication System.” The contents of eachof which are hereby incorporated by reference. Application Ser. No.10/688,470 is also related to commonly owned U.S. Pat. No. 6,922,559,entitled “Unlicensed Wireless Communication Base Station to FacilitateUnlicensed and Licensed Wireless Communications with a SubscriberDevice, and Method of Operation,” filed Apr. 2, 2002 and issued on Jul.26, 2005; application Ser. No. 10/251,901, entitled “Apparatus forSupporting the Handover of a Telecommunication Session between aLicensed Wireless system and an Unlicensed Wireless system,” filed Sep.20, 2002; Provisional Application No. 60/447,575, entitled “MobileStation functionality in Support of a System for Extending the CoverageArea of a Licensed Wireless Communication System using an UnlicensedWireless Communication,” files Feb. 14, 2003; and ProvisionalApplication No. 60/468,336, entitled “Method for Installation ofBroadband Customer Premise Equipment without User/OperatorConfiguration,” files May 5, 2003, the contents of each of which arehereby incorporated by reference in its entirety.

FIELD OF THE INVENTION

This invention relates generally to telecommunications. Moreparticularly, this invention relates to a technique for seamlesslyintegrating voice and data telecommunication services across a licensedwireless system and an unlicensed wireless system.

BACKGROUND OF THE INVENTION

Licensed wireless systems provide mobile wireless communications toindividuals using wireless transceivers. Licensed wireless systems referto public cellular telephone systems and/or Personal CommunicationServices (PCS) telephone systems. Wireless transceivers include cellulartelephones, PCS telephones, wireless-enabled personal digitalassistants, wireless modems, and the like.

Licensed wireless systems utilize wireless signal frequencies that arelicensed from governments. Large fees are paid for access to thesefrequencies. Expensive base station equipment is used to supportcommunications on licensed frequencies. Base stations are typicallyinstalled approximately a mile apart from one another. As a result, thequality of service (voice quality and speed of data transfer) inwireless systems is considerably inferior to the quality of serviceafforded by landline (wired) connections. Thus, the user of a licensedwireless system pays relatively high fees for relatively low qualityservice.

Landline (wired) connections are extensively deployed and generallyperform at a lower cost with higher quality voice and higher speed dataservices. The problem with landline connections is that they constrainthe mobility of a user. Traditionally, a physical connection to thelandline was required.

Currently, unlicensed wireless communication systems are deployed toincrease the mobility of an individual using a landline. The mobilityrange associated with such systems is typically on the order of 100meters or less. A common unlicensed wireless communication systemincludes a base station with a physical connection to a landline. Thebase station has a RF transceiver to facilitate communication with awireless handset that is operative within a modest distance of the basestation. Thus, this option provides higher quality services at a lowercost, but the services only extend a modest distance from the basestation.

Thus, there are significant shortcomings associated with currentlandline systems and licensed wireless systems. For this reason,individuals commonly have one telephone number for landlinecommunications and one telephone number for licensed wirelesscommunications. This leads to additional expense and inconvenience foran individual. It would be highly desirable if an individual couldutilize a single telephone number for both landline communications andlicensed wireless communications. Ideally, such a system would allow anindividual, through seamless handoffs between the two systems, toexploit the benefits of each system.

SUMMARY OF THE INVENTION

A method of integrating a licensed wireless system and an unlicensedwireless system includes initiating a wireless communication session ina first region serviced by a first wireless system and maintaining thewireless communication session in a second region serviced by a secondwireless system. The first wireless system is selected from the groupincluding a licensed wireless system and an unlicensed wireless system.The second wireless system is the unselected system from the groupincluding the licensed wireless system and the unlicensed wirelesssystem.

The invention also allows the subscriber to roam outside the range ofthe unlicensed base station without dropping communications. Instead,roaming outside the range of the unlicensed base station results in aseamless handoff (also referred to as a hand over) wherein communicationservices are automatically provided by the licensed wireless system.

In one embodiment of a system, a mobile station includes a first level1, level 2, and level 3 protocols for a licensed wireless service. Themobile station also includes a second level 1, level 2, and level 3protocols for an unlicensed wireless service. An indoor base station isoperable to receive an unlicensed wireless channel from the mobilestation when the mobile station is within an unlicensed wireless servicearea. An indoor network controller is coupled to the indoor base stationand is adapted to exchange signals with a telecommunications network.The indoor network controller and indoor base station are configured toconvert the second level 1, second level 2, and second level 3 protocolsinto a standard base station controller interface recognized by thetelecommunications network. The mobile station, indoor base station, andindoor network controller are configured to establish a communicationsession on an unlicensed wireless channel using the base stationcontroller interface when the mobile station is within the unlicensedwireless service area.

BRIEF DESCRIPTION OF THE FIGURES

The invention is more fully appreciated in connection with the followingdetailed description taken in conjunction with the accompanyingdrawings, in which:

FIG. 1A provides an overview of the indoor access network (IAN) mobileservice solution in accordance with one embodiment of the presentinvention;

FIG. 1B illustrates protocol layers of a mobile set in accordance withone embodiment of the present invention;

FIG. 1C illustrates a method of protocol conversion in accordance withone embodiment of the present invention;

FIG. 2 illustrates two indoor access network (IAN) options in accordancewith one embodiment of the present invention;

FIG. 3 illustrates an indoor access network (IAN) Broadband architecturein accordance with one embodiment of the present invention;

FIG. 4 illustrates an IAN Hybrid architecture in accordance with oneembodiment of the present invention;

FIG. 5 illustrates components of a GSM mobile set for providing level 1,level 2, and level 3 layers for a licensed wireless service and anunlicensed wireless service in accordance with one embodiment of thepresent invention;

FIG. 6 illustrates components of mobile set for providing level 1, level2, and level 3 layers for a GSM licensed wireless service and anunlicensed wireless service in accordance with one embodiment of thepresent invention;

FIG. 7A illustrates an IAN protocol architecture in support of GSMmobility management (MM) and connection management (CM) signaling, aswell as IAN-specific signaling in accordance with one embodiment of thepresent invention;

FIG. 7B illustrates an IAN protocol architecture in support of GSMmobility management (MM) and connection management (CM) signaling, aswell as IAN-specific signaling in accordance with one embodiment of thepresent invention;

FIG. 8 illustrates an IAN protocol architecture in support of GSM voicetransmission in accordance with one embodiment of the present invention;

FIG. 9 illustrates components for level 1, level 2, and level 3 layersin a GPRS mobile set in accordance with one embodiment of the presentinvention;

FIG. 10 illustrates components for level 1, level 2, and level 3 layersin a GPRS mobile set in accordance with one embodiment of the presentinvention;

FIG. 11A illustrates an IAN protocol architecture in support of GPRSdata transmission in accordance with one embodiment of the presentinvention;

FIG. 11B illustrates an IAN protocol architecture in support of GPRSdata transmission in accordance with one embodiment of the presentinvention;

FIG. 12 illustrates a conventional GSM/GPRS registration area concept inaccordance with one embodiment of the present invention;

FIG. 13 illustrates registration areas for a licensed wireless networkand an unlicensed wireless network in accordance with one embodiment ofthe present invention;

FIG. 14 illustrates registration areas for a licensed wireless networkand an unlicensed wireless network in accordance with one embodiment ofthe present invention.

FIG. 15 illustrates several possible GSM and IAN coverage scenarios inaccordance with one embodiment of the present invention;

FIG. 16 illustrates exemplary message flows involved in the normal,successful case when a mobile station is powered on in an area with bothGSM and IAN coverage in accordance with one embodiment of the presentinvention;

FIG. 17 illustrates exemplary message flows involved in the normal,successful case when a mobile station is powered on in an area with bothGSM and IAN coverage in accordance with one embodiment of the presentinvention;

FIG. 18 illustrates exemplary message flows involved in the normal,successful case when a powered up mobile station enters IAN coveragefrom GSM coverage while in the idle mode in accordance with oneembodiment of the present invention;

FIG. 19 illustrates exemplary message flows involved in the normal,successful case when a powered up, idle mobile station re-enters IANcoverage following a temporary absence and prior to the expiration oftimer T1 in accordance with one embodiment of the present invention;

FIG. 20 illustrates exemplary message flows involved in the normal,successful case when a powered up mobile station re-enters IAN coveragefollowing a temporary absence and after the expiration of timer T1 butprior to the expiration of timer T2 in accordance with one embodiment ofthe present invention;

FIG. 21 illustrates exemplary message flows involved in the normal,successful case when the IBS and mobile station detect the loss of theIAN connection and both timer T1 and T2 expire in accordance with oneembodiment of the present invention;

FIG. 22 illustrates exemplary message flows in a first stage of voicebearer establishment for the IAN broadband architecture in accordancewith one embodiment of the present invention;

FIG. 23 illustrates exemplary message flows in a first stage of bearerestablishment for the IAN hybrid architecture in accordance with oneembodiment of the present invention;

FIG. 24 illustrates exemplary message flows in an optimized IAN voicebearer establishment process associated with the hybrid architecture inaccordance with one embodiment of the present invention;

FIG. 25 illustrates exemplary message flows involved in the normal,successful case for a mobile originated call in accordance with oneembodiment of the present invention;

FIG. 26 illustrates exemplary message flows involved in the normal,successful case for a mobile terminated call in accordance with oneembodiment of the present invention;

FIG. 27 illustrates exemplary message flows involved in the normal,successful case when a IAN-mode call is released by the IAN mobilestation in accordance with one embodiment of the present invention;

FIG. 28 illustrates exemplary message flows involved in the normal,successful case when a IAN-mode call is released by the other, non-IANparty in the call in accordance with one embodiment of the presentinvention;

FIG. 29 is an example of the relay of DTAP supplementary servicemessages in accordance with one embodiment of the present invention;

Like reference numerals refer to corresponding parts throughout theseveral views of the drawings.

DETAILED DESCRIPTION OF THE INVENTION

The present invention is directed towards seamlessly providing wirelessservices to a mobile station (MS) using both a licensed wireless systemand an unlicensed wireless system. The unlicensed wireless system is ashort-range wireless system, which may be described as an “indoor”solution. However, it will be understood through the application thatthe unlicensed wireless system includes unlicensed wireless systems thatcover not only a portion of a building but also local outdoor regions,such as outdoor portions of a corporate campus serviced by an unlicensedwireless system. The mobile station may, for example, be a wirelessphone, smart phone, personal digital assistant, or mobile computer. The“mobile station” may also, for example, be a fixed wireless deviceproviding a set of terminal adapter functions for connecting IntegratedServices Digital Network (ISDN) or Plain Old Telephone Service (POTS)terminals to the wireless system. Representative of this type of deviceis the Phonecell line of products from Telular Corporation of Chicago,Ill. Application of the present invention to this type of device enablesthe wireless service provider to offer so-called landline replacementservice to users, even for user locations not sufficiently covered bythe licensed wireless system. Throughout the following description,acronyms commonly used in the telecommunications industry for wirelessservices are utilized along with acronyms specific to the presentinvention. A table of acronyms specific to this application is includedin Appendix I.

FIG. 1A illustrates an Indoor Access Network (IAN) system 100 inaccordance with one embodiment of the present invention. As indicated byfirst arrow 104, a licensed wireless communication session is conductedwith a mobile station (MB) 102 to a voice or data telecommunicationsnetwork 114 (e.g., including a mobile switching center (MSC) 116 forvoice data or a serving GPRS support node (SGSN) 118 for a datanetwork). The first path 104 includes a wireless channel 106 of alicensed wireless system, a base transceiver station (BTS) 108, privatetrunks 110, and a base station controller (BSC) 112. The base stationcontroller 112 communicates with telecommunications network 114 througha standard base station controller interface 190. For example, the basestation controller 112 may communicate with the MSC via the GSMA-interface for circuit switched voice services and with the SGSN viathe GSM Gb interface for packet data services (GPRS). Conventionallicensed voice and data networks 114 include protocols to permitseamless handoffs from one recognized base station controller 112 toanother base station controller 112 (not shown).

However, if the mobile station is within range of an indoor base station(IBS) 128, a wireless session is conducted using an unlicensed channelof an unlicensed wireless system. In one embodiment, the service area ofindoor base station 128 is an indoor portion of a building, although itwill be understood that the service region of indoor base station 128may include an outdoor portion of a building or campus. As indicated bysecond arrow 124, the mobile station 102 may be connected to thetelecommunications network 114 via a second data path 124 including anunlicensed wireless channel 126, an unlicensed wireless service indoorbase station (IBS) 128, an access network 130, and an indoor networkcontroller (INC) 132 (also described by the inventors of the presentapplication as an “Iswitch”) to voice/data network 114. The indoornetwork controller 132 also communicates with network 114 using a basestation controller interface 190. As described below in more detail,indoor base station 128 and indoor network controller 132 may includesoftware entities stored in memory and executing on one or moremicroprocessors (not shown in FIG. 1A) adapted to perform protocolconversion.

The unlicensed wireless channel 126 may be an unlicensed, free spectrum(e.g., spectrum around 2.4 GHz or 5 GHz). The unlicensed wirelessservice may have an associated communication protocol. As examples, theunlicensed wireless service may be a Bluetooth compatible wirelessservice, or a wireless local area network (IAN) service (e.g., the802.11 IEEE wireless standard). This provides the user with potentiallyimproved quality of service in the service regions of the unlicensedwireless service. Thus, when a subscriber is within range of theunlicensed base station, the subscriber may enjoy low cost, high speed,and high quality voice and data services. In addition, the subscriberenjoys extended service range since the handset can receive servicesdeep within a building. This type of service range is not reliablyprovided by a licensed wireless system. However, the subscriber can roamoutside the range of the unlicensed base station without droppingcommunications. Instead, roaming outside the range of the unlicensedbase station results in a seamless handoff (also referred to as a handover) wherein communication services are automatically provided by thelicensed wireless system, as described in more detail in U.S. patentapplication Ser. No. 10/115,833, the contents of which are herebyincorporated by reference.

Mobile station 102 has a microprocessor and memory (not shown) thatincludes computer program instructions for executing wireless protocolsfor managing communication sessions. As illustrated in FIG. 1B, in oneembodiment the mobile station 102 includes a layer 1 protocol layer 142,layer 2 protocol layer 144, and a layer 3 signaling protocol layer forthe licensed wireless service that includes a radio resource (RR)sublayer 146, a mobility management (MM) sublayer 148, and a callmanagement (CM) layer 150. It will be understood that the level 1, level2, and level 3 layers may be implemented as software modules, which mayalso be described as software “entities.” In accordance with a commonnomenclature for licensed wireless services, layer 1 is the physicallayer, i.e., the physical baseband for a wireless communication session.The physical layer is the lowest layer of the radio interface andprovides functions to transfer bit streams over physical radio links.Layer 2 is the data link layer. The data link layer provides signalingbetween the mobile station and the base station controller. TheRR-sublayer is concerned with the management of an RR-session, which isthe time that a mobile station is in a dedicated mode, as well as theconfiguration of radio channel, power controller, discontinuingtransmission and reception, and handovers. The mobility management layermanages issues that arise from the mobility of the subscriber. Themobility management layer may, for example, deal with mobile stationlocation, security functions, and authentication. The call controlmanagement layer provides controls for end-to-end call establishment.These functions for a licensed wireless system are well known by thosein the art of wireless communication.

In one embodiment of the present invention, the mobile station alsoincludes an unlicensed wireless service physical layer 152 (i.e., aphysical layer for unlicensed wireless service such as Bluetooth,Wireless local area network, or other unlicensed wireless channel). Themobile station also includes an unlicensed wireless service level 2 linklayer 154. The mobile station also includes an unlicensed wirelessservice radio resource sublayer(s) 156. An access mode switch 160 isincluded for the mobile management 148 and call management layers 150 toaccess the unlicensed wireless service radio resource sublayer 156 andunlicensed wireless service link layer 154 when the mobile station 102is within range of an unlicensed wireless service indoor base station128

The unlicensed radio resource sublayer 156 and unlicensed link layer 154may include protocols specific to the unlicensed wireless serviceutilized in addition to protocols selected to facilitate seamlesshandoff between licensed and unlicensed wireless systems, as describedbelow in more detail. Consequently, the unlicensed radio resourcesublayer 156 and unlicensed link layer 154 need to be converted into aformat compatible with a conventional base station controller interfaceprotocol 190 recognized by a MSC, SGSN, or other voice or data network.

Referring to FIG. 1C, in embodiment of the present invention, the mobilestation 102, indoor base station 128 and indoor network controller 132provide an interface conversion function to convert the level 1, level2, and level 3 layers of the unlicensed service into a conventional basestation subnetwork (BSS) interface 190 (e.g., an A-interface or aGb-interface). As a result of the protocol conversion, a communicationsession may be established that is transparent to the voice network/datanetwork 114, i.e., the voice/data network 114 uses its standardinterface and protocols for the communication session as it would with aconventional communication session handled by a conventional basetransceiver station. For example, in some embodiments the mobile station102 and indoor network controller 132 are configured to initiatelocation update and service requests that ordinarily originate from abase station controller. As a result, protocols for a seamless handoffof services that is transparent to voice/data network 114 arefacilitated. This permits, for example, a single phone number to be usedfor both the licensed wireless service and the unlicensed wirelessservice. Additionally, the present invention permits a variety ofservices that were traditionally offered only through licensed wirelessservices to be offered through an unlicensed wireless service. The userthus gets the benefit of potentially higher quality service when theirmobile station is located within the area serviced by a high bandwidthunlicensed wireless service while also having access to conventionalphone services.

The licensed wireless service may comprise any licensed wireless servicehaving a defined BSS interface protocol 190 for a voice/data network114. In one embodiment, the licensed wireless service is a GSM/GPRSradio access network, although it will be understood that embodiments ofthe present invention include other licensed wireless services. For thisembodiment, the indoor network controller 132 interconnects to the GSMcore network via the same base station controller interfaces 190 used bya standard GSM BSS network element. For example, in a GSM application,these interfaces are the GSM A-interface for circuit switched voiceservices and the GSM Gb interface for packet data services (GPRS). In aUMTS application of the invention, the indoor network controller 132interconnects to the UMTS network using a UMTS Iu-cs interface forcircuit switched voice services and the UMTS Iu-ps interface for packetdata services. In a CDMA application of the invention, the indoornetwork controller 132 interconnects with the CDMA network using theCDMA A1 and A2 interfaces for circuit switched voice services and theCDMA A10 and A11 interfaces for packet data services.

In a GSM/GPRS embodiment, indoor network controller 132 appears to theGSM/GPRS core network as a GSM BSS network element and is managed andoperated as such. In this architecture the principle elements oftransaction control (e.g., call processing) are provided by highernetwork elements; namely the MSC 116 visitor location registry (VLR) andthe SGSN. Authorized mobile stations are allowed access to the GSM/GPRScore network either directly through the GSM radio access network ifthey are outside of the service area of an indoor base station or viathe indoor access network system 100 if they are within the service areaof an indoor base station 128.

Since a communication session to the IAN system 100 is transparent to avoice or data network 114, the unlicensed wireless service may supportall user services that are typically offered by the wireless serviceprovider. In the GSM case, this preferably includes the following basicservices: Telephony; Emergency call (e.g., E911 calling in NorthAmerica); Short message, mobile-terminated point-to-point (MT/PP); Shortmessage, mobile-originated point-to-point (MO/PP); GPRS bearer services;Handover (outdoor-to-indoor, indoor-to-outdoor, voice, data, SMS, SS).Additionally for GSM, this preferably includes the followingsupplementary services: Call Deflection; Calling Line IdentificationPresentation; Calling Line Identification Restriction; Connected LineIdentification Presentation; Connected Line Identification Restriction;Call Forwarding Unconditional; Call Forwarding on Mobile SubscriberBusy; Call Forwarding on No Reply; Call Forwarding on Mobile SubscriberNot Reachable; Calling Name Presentation; Call Waiting; Call Hold; MultiParty Service; Closed User Group; Advice of Charge (Information); Adviceof Charge (Charging); User-to-user signaling; Barring of All OutgoingCalls; Barring of Outgoing International Calls; Barring of OutgoingInternational Calls except those directed to the Home PLMN Country;Barring of All Incoming Calls; Barring of Incoming Calls when RoamingOutside the Home PLMN Country; Explicit Call Transfer; Support ofPrivate Numbering Plan; Completion of calls to busy subscribers;Unstructured Supplementary Services Data; SIM Toolkit. Moreover, itpreferably includes Regulatory and Other Services such as: lawfullyauthorized electronic surveillance (also known as “wiretap”); TTY (alsoknown as Telecommunications Device for the Deaf); and Location services.

FIG. 2 illustrates embodiments of the access network 130 configurationfor coupling the indoor base station 128 to the indoor networkcontroller 132. In one embodiment, the access network is broadband only.In this architecture, all traffic between the indoor network controller132 and the customer premise equipment (i.e., indoor base station andmobile station), including all voice service, data service and signalingtraffic, is conveyed using a broadband access network. In a hybridversion, both Broadband and POTS are used. In this architecture, alldata service and signaling traffic between the indoor network controller132 and the customer premise equipment is conveyed using a broadbandaccess network; however, voice traffic is conveyed using common PSTNbearer channels (e.g., POTS or Plain Old Telephone Service). We refer tothis as the “hybrid architecture” in this application.

FIG. 3 illustrates one embodiment of an IAN broadband architecture. A K1interface 305 between the mobile station 102 and the indoor base station128 is illustrated along with a K2 interface 310 between the indoor basestation 128 and indoor network controller 132.

FIG. 4 illustrates an embodiment of a hybrid IAN architecture for GSM.The K1 interface 305 between the mobile station 102 and the indoor basestation 128 and the K2 interface 310 between the indoor base station 128and the indoor network controller 132 is illustrated. These interfacesand techniques for protocol conversion will be described below in moredetail.

FIG. 5 provides an overview of a level 1, level 2, and level 3GSM-related protocol architecture for one embodiment of mobile station102. As illustrated, there are two logical radio resource (RR)management entities: the GSM RR entity 546 and the IAN RR entity 556.The protocol architecture includes a GSM baseband level 1 layer 542, GSMlevel 2 link layer 544, Bluetooth baseband level 1 layer 552, Bluetoothlevel 2 layers 554, access mode switch 560, and upper layer protocols580. When the MS (mobile station) is operating in an IAN mode, the IANRR entity 556 is the current “serving” RR entity providing service tothe mobility management (MM) sublayer via the designated service accesspoint (SAP) (RR-SAP) (shown in FIG. 6). The GSM RR entity is detachedfrom the MM sublayer in this mode. The IAN RR entity 556 is a new set offunctions. IAN-RR entity 556 is responsible for several tasks. First theIAN-RR entity 556 is responsible for discovery of IAN coverage and IANregistration. Second, the IAN-RR entity 556 is responsible for emulationof the GSM RR layer to provide the expected services to the MM layer;i.e., create, maintain and tear down RR connections. In one embodiment,all existing GSM 04.07 primitives defined for the RR-SAP apply. Theplug-in of the IAN RR entity 556 is made transparent to the upper layerprotocols in this way. Third, the IAN-RR entity 556 module isresponsible for coordination with the GSM RR entity to manage accessmode switching and handover.

FIG. 6 illustrates an embodiment of the mobile station 102 showingportions of the level 2 and level 3 layers. In this embodiment, there isprovided IANGSM-SAP 592, GSMIAN-SAP 590 interface handlers for accessmode switching and handover. The IAN RR entity 556 provides coordinationwith the GSM RR entity 546 through the IANGSM-SAP 592, specifically foraccess mode switching and “handout” (i.e., from indoor to outdoor)procedures. The GSM RR entity 546 provides coordination with the IAN RRentity 556 through the GSMIAN-SAP 590, specifically for access modeswitching and “handing over” (i.e., from outdoor to indoor) procedures.The function of mobility management layer 565 and connection managementlayer 570 will be described below in more detail.

FIG. 7A illustrates an embodiment in which an IAN protocol architecturesupports GSM MM and CM signaling, as well as IAN-specific signaling forthe unlicensed wireless service. The MSC sublayers are conventional,well known features known in the art in regards to the message transferpart ((MTP) interfaces 705, signaling connection control part, (SCCP)707, base station system application part (BSSAP) 709, mobilitymanagement interface 711, and connection management interface 713.

The IAN-RR protocol supports the IAN “layer 3” signaling functions. Thisincludes the end-to-end GSM signaling between the indoor networkcontroller 132 and mobile station 102, via IAN-RR message relayfunctions in the indoor base station 128. The indoor network controller132 is responsible for the interworking between these messages and theanalogous A-interface messages. The IAN-RR protocol also supportsIAN-specific signaling between the mobile station 102, indoor basestation 128 and indoor network controller 132; e.g., for mobilestation-to-indoor base station bearer path control.

The radio resource layers in the mobile station include an IAN-RRsub-layer 556 and an IEP sublayer 557. The IAN-radio resource (RR)protocol is conveyed in an IAN Encapsulation Protocol (IEP) over the K1interface 305, with the IEP being administered by the IEP sublayer 555.The IEP packets are transferred over the K1 interface 305 using theservices of an unlicensed wireless service layer 2 connection accessprocedure (L2CAP) link layer.

The IAN-RR protocol is conveyed in an IAN Transfer Protocol (ITP) overthe K2 interface 310 using an ITP module 702. The ITP messages aretransferred using an IAN Secure Tunnel (IST) connection between theindoor base station 128 and the indoor network controller 132. The ISTmay be provided using standard security protocols. The use of thestandard Secure Socket Layer (SSL) protocol 704 running over TCP/IP 706is shown in FIG. 7A. Another option is to use IPSec. An interveningbroadband access system 719 supports lower level IP connectivity.

The ITP module also supports non IAN-RR signaling between the indoorbase station 128 and the indoor network controller 132. This includesthe IBS-to-INC bearer path control signaling. This signaling maytrigger, or be triggered by, IAN-RR signaling. We refer to thissignaling as the indoor base station Management Application Protocol(IBSMAP) 708.

FIG. 7B illustrates an alternate embodiment in which the IAN-specificprotocol functions of indoor base station 128 are moved to mobilestation 102, allowing the use of unlicensed access points that do notsupport IAN-specific functionality but do support generic IPconnectivity; for example, standard Bluetooth or IEEE 802.11b accesspoints. As illustrated, in this embodiment, the SSL-based IAN SecureTunnel and all upper layer protocols terminate on the mobile station.From the perspective of indoor network controller 132, there is nodifference between the embodiment illustrated in FIG. 7A and thatillustrated in FIG. 7B.

FIG. 8 illustrates one embodiment of an IAN protocol architecture insupport of GSM voice transmission. Audio flows over the K1 interface ina format illustrated as the “K1 Audio Format.” For example, the K1 audioformat may be the 64 kbps continuous variable slope delta modulation(CVSD) format running over Synchronous Connection Oriented (SCO)channels, as specified in the Bluetooth V1.1 standards. It is alsopossible to use standard voice over IP techniques using Bluetooth,802.11 or other unlicensed technology over the K1 interface. Audio flowsover the K2 interface in a format illustrated as the “K2 Audio Format.”For example, a number of RTP-based audio formats may be used; e.g.,G.711 (A-law or mu-law) and G.729A. Audio flows over the indoor networkcontroller 132 to MSC interface, A, in 64 kbps pulse code modulation(PCM) format (G.711 A-law or mu-law). If the K2 audio format issomething other than G.711, then transcoding is required in the indoornetwork controller 132; likewise, if the K1 and K2 audio formats are notthe same, then transcoding is required in the indoor base station 128.

FIGS. 9-11 illustrate a corresponding GPRS implementation. FIG. 9provides an overview of the GPRS-related protocol architecture for theIAN mobile station. FIG. 10 shows details of one embodiment of aninternal IAN/GPRS protocol architecture of the mobile station. FIG. 11Ashows the corresponding GPRS signaling mode when the mobile station isoperating using the unlicensed wireless service. FIG. 11B shows thecorresponding GPRS data transmission mode when the mobile station isoperating using the unlicensed wireless service. The IAN GPRS protocolarchitecture effectively enables the tunneling of GPRS signaling anddata packets through the IAN utilizing the unlicensed spectrum; theIAN-GRR protocol serves the same tunneling function as the IAN-RRprotocol, but for packet-switched traffic between the mobile station 102and SGSN 118.

Referring to FIG. 10, the IAN/GPRS architecture includes two logicalGPRS radio resource (RR) entities: the GPRS RLC 905 entity and the IANGRR entity 955. In IAN mode, the IAN GRR entity is the current “serving”RR entity providing service to the logical link control 980 (LLC) layervia the designated service access point (GRR-SAP). The GPRS RLC entityis detached from the LLC layer in this mode.

The IAN-GRR RLC entity 955 is responsible for the following tasks.First, it emulates the GPRS RLC layer 905 to provide the expectedservices to the upper layer protocols. Second, it coordinates with theGPRS RLC 905 entity to manage access mode switching. In one embodiment,the IAN GRR layer includes IANGPRS-SAP and GPRSIAN-SAP interfacehandlers for access mode switching and modified PLMN/cell reselectionbehavior in IAN mode.

The IAN GRR entity 955 provides coordination with the GPRS RLC entity905 through an IAN GPRS-SAP, specifically for access mode switchingprocedures. The GPRS RLC entity 905 provides coordination with the IANGRR entity through the GPRSIAN-SAP, specifically for access modeswitching procedures.

FIG. 11A illustrates an embodiment in which an IAN protocol architecturesupports GPRS signaling. The SGSN layers are conventional, well knownfeatures known in the art in regards to the GPRS network management(NM), packet flow management (PFM), base station system GPRS protocol(BSSGP), network service (NS), GPRS mobility management (GMM), logicallink control (LLC), session management (SM) and short message service(SMS) interfaces. The IAN-GRR protocol supports message encapsulation ortunneling functions. The indoor network controller 132 is responsiblefor terminating the NM, PFM, GMM, BSSGP, and NS layers and for relayingLLC protocol data units (PDUs) conveying GPRS signaling between theIAN-GRR encapsulated form present on the K2 interface and the analogousGb-interface messages. The indoor base station provides simple IAN-GRRmessage relay functions between the K1 and K2 interfaces. The IANprotocol architecture in support of GPRS signaling makes use of the ITP,SSL, TCP/IP, and IEP layers described in reference to FIG. 7A. GPRS datatransmission may also be supported via the architecture of FIG. 11A,whereby LLC PDUs conveying GPRS data packets are relayed by the INC andIBS between the SGSN and MS. FIG. 11B illustrates an alternateembodiment in which the transport protocol on the K2 interface is notthe connection-oriented TCP protocol, but is instead the connectionlessUDP protocol. This approach has the advantage of improved support forapplication protocols that are best matched with connectionlesstransports (e.g., voice over IP). Data transfer security over the K2provided by SSL in FIG. 11A can be provided by IPSec as shown in FIG.11B.

The basic operation of embodiments of the mobile station, base station,and indoor network controller 132 having been described above in regardsto the operation of level 1, level 2, and level 3 layers and voicebearer operation, registration, mobility management, and call managementprocedures will now be discussed for several embodiments.

Conventional licensed wireless systems include procedures for handingoff a communication session to different components of the licensedwireless system. These include, for example, handing off a session todifferent cells under control of the same base station controller,switching cells under control of different base station controllers butbelonging to one MSC, and switching cells under control of differentMSCs. In embodiments of the present invention, these protocols have beenfurther adapted to initiate a handoff of a communication session to theunlicensed wireless system when the mobile station is within range of atleast one indoor base station controller.

FIG. 12 illustrates the concept of registration used for mobilitymanagement in GSM/GPRS. A MSC 116 may have more than one BSC 112 andassociated base station subsystems (BSSs) linked to it, such as BSS112-A and BSS 112-B. The coverage area is split into a plurality oflogical registration areas 1205, such as 1205-x, 1205-y, and 1205-zcalled Location Areas (LA) (for GSM) and Routing Areas (RA) (for GPRS).

A mobile station 102 is required to register with the base subsystem(BSS) of the network each time the serving location area (or routingarea) changes. This provides the network with information regarding thelocation of the mobile station that may, for example, be used todetermine which BTS 108 and BSC 112 will service the communicationsession. One or more location areas identifiers (LAIs) may be associatedwith each visitor location register (VLR) in a carrier's network.Likewise, one or more routing area identifiers (RAIs) may be controlledby a single SGSN. In actual implementations, the number of differentregistration areas controlled by each VLR/SGSN is decided based upon atradeoff between minimizing network paging and location updating load.The fewer registration areas, the less location updates on the systembut the higher the paging load. The higher the number of registrationareas, the lower the system paging load but the higher the number ofuser registrations. A single location area/routing area 1205-y may beassociated with multiple base station subsystems (BSS). If this is thecase, a mobile-terminated call to a subscriber that is registered in aparticular location area will result in paging requests to each BSSassociated with that location area. Note that there is not necessarily aone-to-one relationship between LAI and RAI; there may be multiple GPRSrouting areas within a single location area.

Referring to FIGS. 13 and 14, in embodiments of the present invention,the registration concept is adapted to describe services by one or moreindoor base stations 128 to facilitate roaming and handoff between thelicensed wireless system and the unlicensed wireless system, asdescribed below in more detail. In the present invention, a set of IANLAI/RAI pairs defines a set of at least one indoor base stations 128under the control of one indoor network controller 132. Thus, referringto FIG. 13, a single indoor network controller 132 may have one or moreindoor base stations defining location area/routing areas 1305 and 1310serviced by the unlicensed wireless system. One or more licensedwireless service area local area/routing areas may overlap with the IANLAI/RAI. In a first IAN configuration illustrated in FIG. 13, LocationArea and Routing Area identity or identities are shared between the IANsystem and the umbrella GSM network.

As illustrated in FIG. 13, the indoor network controller 132 may beconnected to a different MSC/SGSN than those that provide the umbrellaGSM/GPRS coverage. For this reason, the mobile set 102 is preferablyprovided with the IAN LAI/RAI pair that is associated with the servingindoor base station 128 by the indoor network controller 132 as part ofthe “IAN Registration” procedure. This information is used in the mobileset to determine Mobility Management actions while the mobile set is“switched-on” in the GSM/IAN domain; e.g., if a location update isrequired upon leaving the indoor coverage area.

In a second umbrella IAN configuration illustrated in FIG. 14, LocationArea and Routing Area identity or identities are not shared between theIAN system and the umbrella GSM network. Consequently, the indoor LAIand RAI 1405 may be substantially different than the outdoor LAI and RAIzones 1410 and 1415. The IAN system is identified by one or a set ofregistration identifiers (LAI and RAI). The IAN mobile stationarbitrates between the two networks and avoids presenting the GSMnetwork with an overload of registration requests during transientconditions; i.e., temporary movement into and out of the IAN network.

In one embodiment, an IAN registration is performed by the mobilestation 102 to manage signal load on the public land mobile network(PLMN) infrastructure. An IAN registration is preferably automaticallyperformed by the mobile set on initial detection of IAN coverage orfollowing a temporary interruption of IAN coverage under certainspecific conditions. As described below in more detail, this proactiveregistration process facilitates seamless handoff for a variety ofenvironments and situations that may be encountered. In one embodiment,an IAN registration does not involve any signaling to the PLMNinfrastructure and is wholly contained within the IAN system (i.e., themobile station, indoor base station and indoor network controller). TheIAN registration message delivered to the indoor network controller 132preferably includes (among other parameters): IMSI; GSM update status,and associated parameters (e.g., LAI and TMSI, if available); GPRSupdate status, and associated parameters (e.g., RAI and P-TMSI, ifavailable).

In one embodiment, the IAN registration procedure is also used by theindoor network controller 132 to provide the mobile station 102 with theoperating parameters associated with the IAN service on the indoor basestation 128. This is analogous to the use of the GSM broadcast controlchannel (BCCH) to transmit system parameters to mobile stations in GSMcells. In this embodiment, the information that is transmitted includes(among other parameters): IAN-LAI (Location Area Identification);IAN-RAI (Routing Area Identification); IAN-CI (Cell Identification);IAN-ARFCN value (for handover purposes); IAN-BSIC value (for handoverpurposes); Attach/Detach Allowed (ATT) flag setting; GPRS networkoperating mode; CELL_RESELECT_OFFSET, used to “bias” GSM cell selectionin favor of cells with the same registration area as the IAN system; BA(BCCH Allocation) List: and Timer values. These parameters are packagedin an IAN-System-Information wrapper. This package is included in theIAN registration response to the mobile station. The package may also beincluded in other messages to the mobile station in the event that asystem parameter update is required.

FIG. 15 illustrates several different radio environments that may beencountered by an IAN mobile station 102. In the first environment, theGSM and IAN coverage are completely separate and non-overlapping. Thesecond possibility shows partially overlapping GSM and IAN coverage. Inthe final scenario, and perhaps the most common, the IAN coverage iscompletely encapsulated within the GSM coverage. An IAN device may poweron in any of these environments and may transition between coverageareas in a number of attached states.

In one embodiment the mobile station 102 scans for both GSM and IANradio coverage at power on or anytime when the mobile station 102 isidle and there is no coverage of any type. If only GSM coverage isdetected, then the normal GSM mobility management procedure isinitiated. If only IAN coverage is detected, then the mobile station 102establishes a link to the indoor base station 128 and waits for aIAN-LINK-ATTACH message from the indoor base station 128. On receipt ofthe IAN-LINK-ATTACH message (indicating that the received signal levelat the indoor base station 128 has passed a predefined threshold), themobile station 102 performs the IAN registration procedure. Based uponthe information returned, the mobile station 102 then determines if afull network registration is required and if so what type (e.g., GSM orGPRS). If both GSM and IAN coverage are detected, then the mobilestation 102 performs the normal GSM mobility management procedure, thenperforms the IAN registration procedure.

There is also the possibility that a mobile user may initially beoutside of the IAN coverage zone but eventually move into the IANcoverage zone. Consequently, in one embodiment, at anytime when themobile station 102 is idle, in GSM coverage and there is no IANcoverage, the mobile station 102 periodically scans for IAN coverage. IfIAN coverage is detected, the mobile station 102 initiates the IANregistration procedure described above.

In some environments, such as inside a building, there may be IANcoverage but no GSM coverage. For this case, it is desirable that GSMscanning and other procedures be performed to enable the mobile station102 to handoff to GSM upon exiting the IAN coverage zone. In oneembodiment, at anytime when the mobile station 102 is idle, in IANcoverage and there is no GSM coverage, the mobile station 102 continuesto perform normal GSM PLMN search procedures. If GSM coverage isdetected, the mobile station 102 records the identification of thepreferred GSM cell for handover or loss of IAN coverage situations. Atanytime when the mobile station is idle, in IAN coverage and there isGSM coverage, the mobile station 102 continues to perform normal GSMcell reselection procedures.

In one embodiment, the mobile station 102 records the identification ofthe preferred GSM cell for handover or loss of IAN coverage situations.At power off with IAN coverage, a detach indication (if required by thePLMN network or normally sent by the mobile station at power off) issent by the mobile station 102 to the PLMN via the IAN. This indicationis encoded per the current GSM mode of operation (e.g., GSM or GPRS). Atanytime when the mobile station 102 is operating in IAN mode (i.e.,after successful IAN registration on the IAN), the mobile station 102takes the CELL_RESELECT_OFFSET value into account in it GSM PLMN searchand cell reselection procedures; i.e., the offset value “encourages” themobile station 102 to show preference for a GSM cell in the sameregistration area as the indoor base station 128.

FIG. 16 illustrates one embodiment of initial registration message flowsbetween the mobile station 102, indoor base station 128, and indoornetwork controller 132 at power-on between a mobile station, indoor basestation, and indoor network controller involved in the normal,successful case when a mobile station is powered on in an area with bothGSM and IAN coverage. This scenario illustrates the case where the IANcell is in the location area where the mobile station was alreadyregistered such that an IMSI ATTACH message is not required and aperiodic location update is also not required. In step a, upon “switchon” the mobile station will search for GSM and IAN coverage. The mobilestation may first find GSM coverage and perform a location update usingthe outdoor network. In step b, IAN coverage is detected; therefore,secure links are established between the mobile station 102 and indoorbase station 128 and (if not already established) between the indoorbase station 128 and indoor network controller 132. In step c, when theindoor base station 128 determines that the received signal from themobile station is acceptable for IAN service, it sends a IAN-LINK-ATTACHmessage to the mobile station 102. In step d, the mobile station 102sends a IAN-REGISTER message to the indoor base station 128. The indoorbase station 128 relays the IAN-REGISTER message to the indoor networkcontroller 132 using IBSAP. The indoor network controller 132 beginsmonitoring for page requests from the GSM network targeted at the mobilestation in question. In step e, the indoor network controller 132returns an IAN-REGISTER-ACK message to the indoor base station 128. Anindication of the CI and LAI associated with the indoor base station 128is included in this message, contained in the IAN-System-Informationparameter. The indoor base station 128 transparently passes thisinformation to the mobile station 102. The indoor base station 128stores an indication that the mobile station 102 is registered for IANservice. In step f, the mobile station has selected a GSM cell based onnormal GSM cell selection procedures. In step g, the mobile station 102has the following information: 1) The GSM update status and associatedparameters stored on the SIM; 2) the selected GSM cell information basedon normal GSM cell selection procedures; 3) the indoor base station 128cell information provided by the indoor network controller 132 (i.e.,this and the GSM cell information allow the mobile station to determinewhether the IAN configuration is type 1 or 2). Based on thisinformation, the mobile station is required to determine if additionalmobility management procedures are necessary. In this example, themobile station determines that no further mobility management procedureis necessary (i.e., that the service state is for NORMAL SERVICE withthe GSM cell selected). In step h, the IAN portion of the mobile stationcontinues in IAN idle mode.

FIG. 17 illustrates one embodiment of registration message flows andlocation update message flows at power-on involved in the normal,successful case when a mobile station is powered on in an area with bothGSM and IAN coverage. This scenario illustrates the case (for example)where the IAN cell is in the location area where the mobile station wasalready registered, but an IMSI Attach or Location Update is required.Steps a-f are the same as those described with respect to FIG. 16. Inthe example of FIG. 17, in step g, the mobile station determines that alocation update via the IAN is necessary. In step h, the mobile station102 requests the establishment of a logical IAN-RR session from theindoor base station 128 using the IAN-RR-REQUEST message. This messageincludes the resources that are required for the session (e.g.,signaling channel only or signaling channel and voice channel). Theindoor base station 128 verifies that it can provide the necessaryresources to handle the request (i.e., air interface resources andindoor network controller connectivity). In step i, the indoor basestation 128 signals its acceptance of the IAN-RR session request. Insteps j-m, location update signaling takes place between the mobilestation 102 and MSC 116. In step n, the MSC 116 sends the CLEAR-COMMANDmessage to the indoor network controller 132 to release the radioresource. In step o, the indoor network controller 132 acknowledges therelease of the radio resources in the CLEAR-COMPLETE message. The SCCPconnection associated with the session between the indoor networkcontroller 132 and the MSC 116 is released (signaling not shown). Instep p, the indoor network controller 132 signals the indoor basestation 128 to release the IAN-RR session and associated resources viathe IAN-RR-RELEASE message. The indoor base station 128 forwards themessage to the mobile station. In step q, the mobile stationacknowledges the release of the previously established IAN-RR session,using the IAN-RR-RELEASE-COMPLETE message. The indoor base station 128forwards the acknowledgement to the indoor network controller 132. Instep r, the mobile station 102 continues in IAN idle mode.

FIG. 18 illustrates one embodiment of registration message flowsinvolved in the normal, successful case when a powered up mobile station102 enters IAN coverage from GSM coverage while in the idle mode. Instep a, the mobile station 102 performs the appropriate GSM mobilitymanagement procedure (e.g., normal or periodic location update or IMSIattach) while in GSM coverage. This may involve communication betweenthe MSC and the home location register (HLR) using standard protocolssuch as the Mobile Application Part (MAP) protocol. In step b, IANcoverage is detected. Steps c-f are the same as steps b-e in FIG. 17. Instep g, the mobile station 102 determines that no further mobilitymanagement procedure is necessary. In step h, the mobile station beginsIAN idle mode operation.

FIG. 19 illustrates embodiment of attachment/detachment message flowsinvolved in the normal, successful case when a powered up, idle mobilestation 102 re-enters IAN coverage following a temporary absence andprior to the expiration of a timer T1. In step a, the mobile station 102is in IAN idle mode operation. In step b, the indoor base station 128determines that the received signal from the mobile station is no longeracceptable for IAN service. The indoor base station 128 sends aIAN-LINK-DETACH message to the mobile station 102. The mobile station102 starts timer T1. If the link is lost before the indoor base station128 can send IAN-LINK-DETACH, the mobile station 102 and indoor basestation 128 start timers T1 and T2, respectively. If the link is lostafter sending IAN-LINK-DETACH, the indoor base station 128 starts timerT2. At some later point, the mobile station 102 and indoor base station128 may re-establish the IAN link, in which case the indoor base station128 stops timer T2. The secure link between the indoor base station 128and indoor network controller 132 is still established. In step c, theindoor base station 128 determines that the received signal from themobile station 102 is acceptable for IAN service and sends aIAN-LINK-ATTACH message to the mobile station, prior to the expiry oftimer T1. The mobile station 102 stops timer T1. In step d, the mobilestation 102 continues in IAN idle mode operation.

FIG. 20 illustrates an embodiment of detach, attach, and registrationmessage flows involved in the normal, successful case when a powered upmobile station re-enters IAN coverage following a temporary absence andafter the expiration of timer T1 but prior to the expiration of timerT2. Steps a-b are the same as in the previous example of FIG. 19. Instep c, timer T1 expires at the mobile station 102. In step d, the IANapplication directs the mobile station 102 to resume normal GSM MMoperation. The mobile station 102 selects the GSM cell, which has thesame LAI as the IAN IBS; therefore, there is no need for a locationupdate. In step e, the indoor base station 128 determines that thereceived signal from the mobile station 102 is now acceptable for IANservice. The indoor base station 128 sends an IAN-LINK-ATTACH message tothe mobile station 102. Note that between step-b and step-e, the linkbetween the mobile station and indoor base station 128 may be lost andthen re-established. In step f, the mobile station 102 sends anIAN-REGISTER message to the indoor base station 128. In step g, sincethe indoor base station 128 considers the mobile station 102 to still beactive, it returns an IAN-REGISTER-ACK message to the mobile station 102without notifying the indoor network controller 132. The indoor basestation 128 includes the previously stored IAN-System-Informationparameter. In step h, the mobile station determines that no furthermobility management procedure is necessary. In step I, the IANapplication suspends GSM MM procedures and begins IAN idle modeoperation.

FIG. 21 illustrates one embodiment of detachment and deregistrationmessage flows involved in the normal, successful case when the indoorbase station 128 and mobile station 132 detect the loss of the IANconnection and both timers T1 and T2 expire for the idle mode. In stepa, the mobile station 102 is in IAN idle mode operation. In step b, theindoor base station 128 determines that the received signal from themobile station 102 is no longer acceptable for IAN service. The indoorbase station 128 sends an IAN-LINK-DETACH message to the mobile station102. The mobile station starts timer T1. If the link is lost before theindoor base station 128 can send IAN-LINK-DETACH, the mobile station 102and indoor base station 128 may start timers T1 and T2, respectively. Instep c, the link between the mobile station 102 and indoor base station128 is lost. The indoor base station 128 starts timer T2. In step d,timer T1 expires at the mobile station 102. In step e, the IANapplication directs the mobile station 102 to resume normal GSM MMoperation. The mobile station 102 selects the GSM cell, which has thesame LAI as the IAN IBS; therefore, there is no need for a locationupdate. The mobile station 102 may also find that no GSM coverage isavailable, in which case it proceeds per normal GSM procedures. In stepf, timer T2 expires at the indoor base station 128. In step g, theindoor base station 128 sends an IAN-DEREGISTER message to the indoornetwork controller 132 containing the reason for the deregistration(i.e., loss of IAN link). The indoor base station 128 releases anyresources assigned to the mobile station 102. The indoor networkcontroller 132 changes the mobile station state to “Inactive” or asimilar state. Subsequent page requests for the mobile station 102 fromthe GSM network are ignored.

FIG. 22 illustrates an embodiment of channel activation and assignmentrequest message flows for Voice bearer establishment for the IANbroadband architecture. FIG. 23 illustrates an embodiment of theanalogous case for the IAN hybrid architecture. The indoor networkcontroller 132 provides the signaling interworking functionality thatallows the switched establishment of bearer paths between the MSC 116and the indoor base station 128.

In one embodiment, voice bearer establishment between the MSC 116 andthe mobile station 102 takes place in three stages in the IAN broadbandarchitecture solution: First, the indoor network controller 132establishes a connection to the MSC-INC circuit allocated by the MSC 116during the A-interface circuit assignment process. In the broadbandarchitecture, this is a TDM-to-VoIP connection, converting the TDMchannel to the MSC 116 into a VoIP channel to the indoor base station128. Second, the indoor network controller 132 sends a message to theindoor base station 128, directing it to establish VoIP connectivity tothe VoIP channel established in step one. Finally, the indoor basestation 128 directs the mobile station 102 to establish a voice linkover the unlicensed air interface, and the indoor base station 128connects this channel to the channel established in step two.Acknowledgements are returned from mobile station 102 to indoor basestation 128 to indoor network controller 132 to MSC 116, completing theprocess.

In both cases illustrated in FIGS. 22-23, the GSM mobile originating andmobile terminating voice call signaling is exchanged between the mobilestation 102 and the indoor network controller 132, flowing over the IANSecure Tunnel between the indoor network controller 132 and the indoorbase station 128. The indoor network controller 132 provides thenecessary interworking between this signaling and the A-interfacesignaling to the MSC 116. During the call setup process the MSC 116sends a BSSAP Assignment-Request message over the A-interface to theindoor network controller 132. A Circuit Identity Code (CIC) identifyinga DS0 path between the MSC 116 and the indoor network controller 132 isprovided in this message. The DS0 terminates on the media gatewayelement within the indoor network controller 132. In the broadband case,on reception of the BSSAP Assignment Request message: The indoor networkcontroller 132 translates the Assignment-Request message into a voiceover IP (VoIP) call setup request to the IP address associated with theindoor base station 128. The indoor network controller 132 sends aIBSMAP-ACTIVATE-CH message to the indoor base station 128. This messagetriggers VoIP channel establishment in the indoor base station 128. Theindoor base station 128 sends a IAN-ACTIVATE-CH message to the mobilestation 102, triggering voice link establishment over the air interface.The mobile station 102 sends acknowledgement (IAN-ACTIVATE-CH-ACK) tothe indoor base station 128 and the indoor base station 128 sendsacknowledgement (IBSMAP-ACTIVATE-CH-ACK) to the indoor networkcontroller 132. The indoor network controller 132 translates theIBSMAP-ACTIVATE-CH-ACK message from the indoor base station 128 into aBSSAP Assignment Complete message, completing the process.

Referring to the hybrid case of FIG. 23, the indoor network controller132 translates the Assignment-Request message into a ISUP call setuprequest to the PSTN phone number associated with the indoor base station128. The indoor base station 128 answers the call (i.e., goes off-hook)and the indoor network controller 132 translates the ISUP answer signalinto a BSSAP Assignment-Complete message. Using ISUP signaling allowsthis connection to take place in sub-second timeframes. The indoornetwork controller 132 Application Server subsystem controls the MediaGateway subsystem via MGCP or Megaco (H.248) signaling to provide theswitching between the TDM circuit from the MSC and the TDM circuit tothe PSTN.

Referring to FIG. 24, in one embodiment a further indoor networkcontroller optimization is supported in a hybrid approach. The voicebearer is in the form of TDM DS0 circuits in the indoor networkcontroller 132 from the MSC 116 and TDM DS0 circuits out of the indoornetwork controller 132 to the PSTN (or, potentially, a tandem switch inthe PLMN), thus the media gateway function is not necessary, as shown inFIG. 24. In this case, the indoor network controller 132 performs onlysignaling interworking between the A-interface BSSAP protocol and theISUP protocol. This strategy assumes that the MSC 116 is configured toprovide the circuit allocation function (i.e., the assignment of DS0s).This is the normal operating mode in GSM networks(non-remote-MSC-transcoder operation) as opposed to the alternativewhere the BSC provides this function. Circuits may be allocated in poolsat the MSC 116. A pool of circuits will be required for the support ofthe indoor network controller 132. These bearer circuits will of coursenot be directly connected to the indoor network controller 132 butrather to a voice switch. The MSC 116 may need to allocate GSMdescriptors (full rate, half rate etc.) to this trunk pool. For indoornetwork controller support, these channels may be described in the samemanner as full rate channels; however, this description will bear norelevance to the IAN system. No transcoding and rate adaptation unit(TRAU) resources will be required for the origination or termination ofIAN calls.

FIGS. 25-29 illustrate the message flows involved for various callmanagement scenarios via the IAN network.

FIG. 25 illustrates the message flows involved in the normal, successfulcase of a mobile originated call that includes registration with theindoor network controller 132, service request to the MSC 116,assignment requests, establishment of a voice channel, and connection.In step a, the mobile station 102 is registered for IAN service on theindoor network controller 132. In step b, the user enters or selects acalled party number (B) and presses SEND. In step c, the mobile stationrequests the establishment of a logical IAN-RR session from the indoorbase station 128 using the IAN-RR-REQUEST message. This message includesthe resources that are required for the session (i.e., signaling channeland voice channel). The indoor base station 128 verifies that it canprovide the necessary resources to handle the request (i.e., airinterface resources and indoor network controller connectivity). In stepc, the indoor base station 128 signals its acceptance of the IAN-RRsession request. In step d, the mobile station 102 sends aCM-SERVICE-REQUEST message to the indoor base station 128. The indoorbase station 128 relays the message to the indoor network controller 132in an IBSAP message. The IBSAP header contains the mobile stationidentification, which is used to access the mobile station's 102 IANrecord in the indoor network controller 132. The indoor networkcontroller 132 constructs a DTAP CM-SERVICE-REQUEST message. Theidentifier included is the identifier provided by the mobile station.This message is encapsulated inside a BSSMAP COMPLETE-LAYER-3-INFOmessage and sent to the MSC 116. In an optional step e, the MSC 116 mayinitiate the standard GSM authentication procedure.

In step f, if ciphering is not necessary, the MSC 116 signals serviceacceptance via the CM-SERVICE-ACCEPT message. The indoor networkcontroller 132 relays this message to the mobile station 102. Theprocedure continues at step-g. If ciphering is necessary from the MSC'sperspective (not shown in figure), the MSC 116 sends a BSSMAPCIPHER-MODE-COMMAND message to the indoor network controller 132,including the Encryption Information parameter. The indoor networkcontroller 132 relays this to the mobile station 102 in theCIPHER-MODE-COMMAND message. The mobile station 102 responds with aCIPHER-MODE-COMPLETE message, which the indoor network controller 132encapsulates in a BSSMAP CIPHER-MODE-COMPLETE message to the MSC 116.The mobile station 102 stores the Cipher Mode Setting. Note that this isonly needed to enable ciphering if the call is subsequently handed overto GSM; the request for GSM ciphering does not result in the activationof GSM ciphering for the IAN call. If the BSSMAP CIPHER-MODE-COMMANDmessage includes an identity request (i.e., Cipher Response Modeparameter indicates IMEISV request), then the mobile station 102includes the mobile station identity in the CIPHERING-MODE-COMPLETEmessage.

Receipt of either the CM-SERVICE-ACCEPT message or theCIPHER-MODE-COMMAND message indicates to the mobile station 102 that theMM connection is established. In step g, on receipt of a confirmationthat the MM connection is established (i.e., receipt of theCM-SERVICE-ACCEPT), the mobile station 102 sends a SETUP message to theindoor network controller 132 and the indoor network controller 132relays a DTAP SETUP message to the MSC 116. The Bearer Capability IEindicates “speech”. In step h, a DTAP CALL-PROCEEDING message isreturned to the indoor network controller 132 by the MSC 116. Thismessage is delivered to the mobile station. In step i, a BSSMAPASSIGNMENT-REQUEST message is sent by the MSC 116 to the indoor networkcontroller 132. A circuit identity code (CIC) for the selected trunk isincluded in this message. In step j, The indoor network controller 132establishes a media gateway connection to the endpoint identified by theCIC. In step k, the indoor network controller 132 sends aIBSMAP-ACTIVATE-CH message to the indoor base station 128; this messagetriggers VoIP channel establishment in the indoor base station 128. Theindoor base station 128 relays an IAN-ACTIVATE-CH message to the mobilestation 102, triggering voice link establishment between the mobilestation 102 and indoor base station 128. In step 1, the mobilestation-IBS and IBS-INC voice channels are now established and a voicepath exists between the indoor network controller 132 and mobile station102.

In step m, the mobile station returns an IAN-ACTIVATE-CH-ACK message tothe indoor base station 128 and the indoor base station 128 returns anIBSMAP-ACTIVATE-CH-ACK message to the indoor network controller 132. Theindoor network controller 132 sends a BSSMAP ASSIGNMENT-COMPLETE messageto the MSC 116. An end to end bearer path is now established between theMSC 116 and mobile station 102. In step n, the MSC 116 constructs anISUP IAM using the B subscriber address, and sends it towards the calledparty's destination exchange PSTN 2505. In step o, the destinationexchange responds with an ISUP ACM message. The MSC 116 sends a DTAPALERTING or PROGRESS message to the indoor network controller 132. Themessage is propagated to the mobile station 102. ALERTING is used, forexample, to direct the mobile station 102 to provide a ringback signalto the calling user; PROGRESS is used, for example, to notify the mobilestation that the ringback signal is available inband from the network.Either way, the user hears the ringback tone. In step p, the calledparty answers and the destination exchange indicates this with an ISUPACM message. The MSC 116 sends a DTAP CONNECT message to the indoornetwork controller 132. This in turn is delivered to the mobile station102. In step q, a chain of acknowledgements are returned completing thetwo way path at each hop. In step r, the end-to-end two way path is nowin place and voice communication begins.

FIG. 26 illustrates the message flows involved in the normal, successfulcase for a mobile terminated IAN-mode call. Step a shows the mobilestation 102 is registered for IAN service on the indoor networkcontroller 132. In step b, the GMSC receives a call from party Aintended for the IAN subscriber from PSTN 2505.

In step c, the GMSC 2605 queries the home location register (HLR) 2610for routing, sending the MAP Send-Routing-Information request message.The HLR 2610 queries the current serving MSC 116 using the MAPProvide-Roaming-Number request message. In step d, the MSC 116 returns aroaming number, MSRN, in the MAP Provide-Roaming-Number response messageand the HLR 2610 relays this to the GMSC 2605 in the MAPSend-Routing-Information response message. In step e, the GMSC 2605relays the call to the MSC 116. In step f, the MSC 116 sends a BSSMAPPAGING message to all BSCs in the location area, including the indoornetwork controller. The indoor network controller 132 retrieves the userIAN record corresponding to the IMSI in the PAGING message. If no recordis found, or a record is found but the user is not in the active state,the indoor network controller 132 ignores the PAGING message. Otherwise,it sends an IKN-PAGING-REQUEST message to the mobile station. In step g,the mobile station requests the establishment of a logical IAN-RRsession from the indoor base station 128 using the IAN-RR-REQUESTmessage. This message includes the resources that are required for thesession (i.e., signaling channel and voice channel). The indoor basestation 128 verifies that it can provide the necessary resources tohandle the request (i.e., air interface resources and indoor networkcontroller connectivity). In step h, the indoor base station 128 signalsits acceptance of the IAN-RR session request. In step I, the mobilestation sends an IAN-PAGING-RESPONSE message to the indoor networkcontroller. In step j, optionally, the MSC 116 may initiate the standardGSM authentication procedure. If ciphering is necessary from the MSC's116 perspective (not shown in figure), the MSC 116 sends a BSSMAPCIPHER-MODE-COMMAND message to the indoor network controller 132,including the Encryption Information parameter. The indoor networkcontroller 132 relays this to the mobile station in theCIPHER-MODE-COMMAND message. The mobile station 102 responds with aCIPHER-MODE-COMPLETE message, which the indoor network controller 132encapsulates in a BSSMAP CIPHER-MODE-COMPLETE message to the MSC 116.The mobile station stores the Cipher Mode Setting. Note that this isonly needed to enable ciphering if the call is subsequently handed overto GSM; the request for GSM ciphering does not result in the activationof GSM ciphering for the IAN call. If the BSSMAP CIPHER-MODE-COMMANDmessage includes an identity request (i.e., Cipher Response Modeparameter indicates IMEISV request), then the mobile station 102includes the mobile station identity in the CIPHERING-MODE-COMPLETEmessage.

In step k, the MSC sends a DTAP SETUP message to the indoor networkcontroller. The indoor network controller 132 relays the message to themobile station 102. In step 1, on receipt of the SETUP message, themobile station sends a CALL-CONFIRMED message to the indoor networkcontroller 132. A DTAP CALL-CONFIRMED message is returned to the MSC 116by the indoor network controller 132. Steps i-m are the same as thosedescribed above for FIG. 24. In step r, the user is alerted. The mobilestation 102 sends an ALERTING message to the indoor network controller132 to indicate that the user is being alerted. The indoor networkcontroller 132 translates this into a DTAP ALERTING message, and the MSC116 returns an ISUP ACM message to the GMSC which forwards an ACM to theoriginating exchange. In step s, the user answers. The mobile station102 sends a CONNECT message to the indoor network controller 132 toindicate that the user has answered. The indoor network controller 132translates this into a DTAP CONNECT message, and the MSC 116 returns anISUP ANM message to the GMSC which forwards an ANM to the originatingexchange. In step t, a chain of acknowledgements are returned completingthe two way path at each hop. In step u, the end-to-end two way path isnow in place and voice communication begins.

FIGS. 27-28 illustrate examples of call release by an IAN subscriber.FIG. 27 illustrates the message flows involved in the normal, successfulcase when an IAN-mode call is released by the mobile station 102. Instep a, the IAN subscriber ends the call (e.g., by pressing the ENDbutton). The mobile station 102 sends a DISCONNECT message to the indoornetwork controller 132 and the indoor network controller 132 relays aDTAP DISCONNECT message to the MSC 116. The MSC 116 sends an ISUPRELEASE message towards the other party. In step b, the MSC 116 sends aDTAP RELEASE message to the indoor network controller 132. The indoornetwork controller 132 relays this to the mobile station 102. In step c,the mobile station 102 sends a RELEASE-COMPLETE message to the indoornetwork controller 132 and the indoor network controller 132 relays aDTAP RELEASE-COMPLETE message to the MSC. At this point, the MSC 116considers the connection released. The MSC 116 should have received aISUP RLC message from the other party's exchange. In step d, the MSC 116sends BSSMAP CLEAR COMMAND to the indoor network controller 132indicating a request to release the old resources. The SCCP ConnectionIdentifier is used to determine the corresponding call. In step e, theindoor network controller 132 releases the INC-to-MSC circuit associatedwith the call. In step f, the indoor network controller 132 acknowledgesthe release in a BSSMAP CLEAR-COMPLETE message to the MSC 116. The SCCPconnection associated with the call between the indoor networkcontroller 132 and the MSC 116 is released (signaling not shown). Instep g, the indoor network controller 132 sends an IAN-RR-RELEASEmessage to the indoor base station 128. The indoor base station 128relays the message to the mobile station 102. In step h, the mobilestation 102 and the indoor base station 128 releases the voice channelsand other resources allocated for the call. In step i, the mobilestation 102 confirms the call release with the IAN-RR-RELEASE message tothe indoor base station 128 and the indoor base station 128 relays thismessage to the indoor network controller 132.

FIG. 28 illustrates the message flows involved in the normal, successfulcase when a IAN-mode call is released by the other, non-IAN party in thecall. Referring to step a, the other party ends the call (e.g., byhanging up). The MSC 116 receives a ISUP RELEASE message from the otherparty's exchange. The MSC 116 sends a DTAP DISCONNECT message to theindoor network controller 132 and the indoor network controller 132relays a DISCONNECT message to the mobile station 102. In step b, themobile station 102 sends a RELEASE message to the indoor networkcontroller 132. The indoor network controller 132 relays this to the MSC116 in the DTAP RELEASE message. The MSC 116 sends a ISUP RLC messagetowards the other party. In step c, the MSC 116 sends a DTAPRELEASE-COMPLETE message to the indoor network controller 132 and theindoor network controller 132 relays a RELEASE-COMPLETE message to themobile station 102. Steps d-i are similar to those described above inregards to FIG. 27.

Embodiments of the present invention also permit supplementary GSMservices to be provided. GSM has standardized a large number ofservices. Beyond call origination and termination, the followingservices shall be supported by the IAN system: Service Standard (Stage3); Short Message Services 04.11; Supplementary Service Control 04.80;Calling Line Identification Presentation (CLIP) 04.81; Calling LineIdentification Restriction (CLIR) 04.81; Connected Line IdentificationPresentation (CoLP) 04.81; Connected Line Identification Restriction(CoLR) 04.81; Call Forwarding Unconditional 04.82; Call Forwarding Busy04.82; Call Forwarding No Reply 04.82; Call Forwarding Not Reachable04.82; Call Waiting (CW) 04.83; Call Hold (CH) 04.83; Multi Party (MPTY)04.84; Closed User Group (CUG) 04.85; Advice of Charge (AoC) 04.86; UserUser Signaling (UUS) 04.87; Call Barring (CB) 04.88; Explicit CallTransfer (ECT) 04.91; and Name Identification 04.96.

These supplementary services involve procedures that operate end-to-endbetween the mobile station 102 and the MSC 116. Beyond the basic GSM04.08 direct transfer application part (DTAP) messages already describedfor MO and MT calls, the following 04.08 DTAP messages are used forthese additional supplementary service purposes: CP-DATA; CP-ACK;CP-ERROR; REGISTER; FACILITY; HOLD; HOLD-ACKNOWLEDGE; HOLD-REJECT;RETRIEVE; RETRIEVE-ACKNOWLEDGE; RETRIEVE-REJECT; RETRIEVE-REJECT;RETRIEVE-REJECT; RETRIEVE-REJECT; USER-INFORMATION; CONGESTION-CONTROL.These DTAP message are relayed between the mobile station 102 and MSC116 by the indoor base station 128 and indoor network controller 132 inthe same manner as in the other call control and mobility managementembodiments.

FIG. 29 illustrates one embodiment of message flows for providingsupplementary GSM services. Referring to step a, an MM connection isestablished between the mobile station 102 and the MSC 116 for anongoing call. In step b, a user requests a particular supplementaryservice operation (e.g., to put the call on hold). In step c, the mobilestation 102 sends the HOLD message over the K1 interface to the indoorbase station 128. The indoor base station 128 relays the HOLD messageover the K2 interface to the indoor network controller 132. The indoornetwork controller 132 relays the DTAP HOLD message to the MSC 116 overthe A-interface. In step d, the DTAP HOLD-ACK message is sent from MSC116 to mobile station 102 in an analogous manner. In step e, later inthe call, the user requests another supplementary service operation(e.g., to initiate a MultiParty call). In step f, the mobile stationsends the FACILITY message over the K1 interface to the indoor basestation 128. The indoor base station 128 relays the FACILITY messageover the K2 interface to the indoor network controller 132. The indoornetwork controller 132 relays the DTAP FACILITY message to the MSC 116over the A-interface. In step g, the DTAP FACILITY message containingthe response is sent from MSC 116 to mobile station 102 in an analogousmanner.

It will be understood that an embodiment of the present inventionrelates to a computer storage product with a computer-readable mediumhaving computer code thereon for performing various computer-implementedoperations. The media and computer code may be those specially designedand constructed for the purposes of the present invention, or they maybe of the kind well known and available to those having skill in thecomputer software arts. Examples of computer-readable media include, butare not limited to: magnetic media such as hard disks, floppy disks, andmagnetic tape; optical media such as CD-ROMs and holographic devices;magneto-optical media such as optical disks; and hardware devices thatare specially configured to store and execute program code, such asapplication-specific integrated circuits (“ASICs”), programmable logicdevices (“PLDs”) and ROM and RAM devices. Examples of computer codeinclude machine code, such as produced by a compiler, and filescontaining higher-level code that are executed by a computer using aninterpreter. For example, an embodiment of the invention may beimplemented using Java, C++, or other object-oriented programminglanguage and development tools. Another embodiment of the invention maybe implemented in hardwired circuitry in place of, or in combinationwith, machine-executable software instructions.

The foregoing description, for purposes of explanation, used specificnomenclature to provide a thorough understanding of the invention.However, it will be apparent to one skilled in the art that specificdetails are not required in order to practice the invention. Thus, theforegoing descriptions of specific embodiments of the invention arepresented for purposes of illustration and description. They are notintended to be exhaustive or to limit the invention to the precise formsdisclosed; obviously, many modifications and variations are possible inview of the above teachings. The embodiments were chosen and describedin order to best explain the principles of the invention and itspractical applications, they thereby enable others skilled in the art tobest utilize the invention and various embodiments with variousmodifications as are suited to the particular use contemplated. It isintended that the following claims and their equivalents define thescope of the invention.

1. A mobile station comprising: a) a first wireless interface to accessa licensed wireless communication network comprising a mobile switchingcenter (MSC); b) a second wireless interface to access an unlicensedwireless communication network via an unlicensed wireless base stationusing an unlicensed radio frequency; c) a third interface to communicatewith an unlicensed wireless network controller communicatively coupledto the base station via a broadband network; and d) circuits forhandling a set of unlicensed radio resource (RR) messages transmittedover the third interface to support assigning a voice bearer channel forthe mobile station to access voice bearer services of the licensedwireless communication system via the unlicensed wireless communicationsystem, wherein the set of unlicensed RR messages includes: an activatechannel message received at the mobile station from the unlicensednetwork controller, said activate channel message sent from theunlicensed network controller to the mobile station in response toreceiving an assignment request from the (MSC), said activate channelmessage triggering establishment of the voice bearer channel for themobile station.
 2. The mobile station of claim 1 wherein the set ofunlicensed RR messages further includes: an activate channelacknowledgment message sent by the mobile station to the unlicensednetwork controller in response to receiving the activate channelmessage.
 3. A mobile station, comprising: a) a first wireless interfaceto access a telecommunications network employed by a licensed wirelesscommunication system; b) a second wireless interface to access anunlicensed wireless communication network via an unlicensed wirelessbase station using an unlicensed radio frequency; c) a third interfaceto communicate with an unlicensed wireless network controllercommunicatively coupled to the base station via a broadband network; andd) circuits for handling a set of unlicensed radio resource (RR)messages transmitted over the third interface to support paging themobile station via the unlicensed network controller, wherein the set ofunlicensed RR messages includes: a PAGING REQUEST message received atthe mobile station from the unlicensed network controller identifyingthe mobile station.
 4. The mobile station of claim 3 wherein the set ofunlicensed RR messages includes: a PAGING RESPONSE message sent from themobile station to the unlicensed network controller in response toreceiving the unlicensed RR PAGING REQUEST.
 5. The mobile station ofclaim 1 wherein said third interface uses Voice over Internet Protocol(VoIP).